1) Field of the Invention
The invention relates to a pin joint in an aircraft fuselage. More particularly, the invention relates to a trapezoidal panel pin joint allowing free deflection between the fuselage and the wing of an aircraft.
2) Description of Related Art
In aircraft, large deflections between the wing and the fuselage due to wing bending can cause design and durability problems in the fuselage and fuselage to wing attachment structure. Known aircraft have wing to fuselage attachment structure that have accounted for this differential deflection by separating the top of the wing box and the fuselage with a horizontal flexible tee member. Known aircraft have a trapezoidal panel that is an extension of the wing rib at the wing/fuselage joint. Known trapezoidal panel designs have accounted for the differential deflection between the wing and the fuselage/fixed pressure deck by vertically separating the trapezoidal panel and fixed pressure deck, allowing the fuselage skin panel and frames to deflect over a relatively long vertical distance. Thus, wing deflection is absorbed by bending of the fuselage frames and skin panels above the trapezoidal panel. Known metallic fuselage designs use stiffened fuselage panels and physical separation to enable the deflection that occurs at the wing rear main spar. However, such known designs can have less vertical distance to incur the large wing deflections, and this can induce stresses to the wing and fuselage. This can increase the risk of durability of the parts, can require more structure, and can increase the weight of the aircraft. In addition, known designs only release one rotational degree of freedom.
Accordingly, there is a need for an improved pin joint design in an aircraft fuselage that does not have the problems associated with known designs.